Ventana software support forum

Hi

I join a vpm file with a model and different seed values showing that the average Bernouilli value does not converge properly towards the original frequency depending on the seed value.

Best regards.

JJ

other vdf files

I'm not convinced that there's a problem. I used the attached modified model to run a sample of 1000 realizations at once, and looked at the statistics for the cumulated "input". The expected value of the standard deviation of "input" given by the binomial distribution is sqrt(100000*0.2*(1-0.2))=126.5. In 2 tests with different seeds I got ~123 and 129. So, I think your threshold for "strangeness" is too strict, because .001*100000 < 126.5.

Forgot the attachment:

Hi Tom

You are right. In fact if one applies Tchebychev inequailty that sets the maximum probability that the gap is more than the epsilon, one finds 1.6, whch means that there is no limitation to the likelyhood of that event happening. I have tested that the Techbychev inequatily that proves that the precision of the estimation of the average increases with the number of draws, works for any seed, any epsilon and any number of draws. See the model joined.
In fact I have a model where I have about 8000 draws and a frequency of 0.2 and with a seed of 4000, I get an estimation of the frequency a little more than 0.21. In that case with the Tchebychev inequality there is a 0.16 maximum probability of this event happening.

Thank you for your help.

Best regards.

JJ